The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Automatic transmissions utilized in modern motor vehicles typically incorporate a device commonly referred to as a hydrodynamic torque converter or simply a torque converter. The torque converter automatically disengages the rotating engine output shaft from the transmission input shaft during vehicle idle conditions to enable the vehicle to stop without stalling the engine. The torque converter also functions as a torque multiplier which increases engine torque delivered to the transmission in the lower speed range until torque converter output speed approximately matches the input (engine) speed.
Because all of the powertrain energy from the engine traverses the torque converter, its performance is critical to the overall performance of the powertrain and vehicle. Such factors as acceleration, shift points, shift smoothness and fuel economy are all affected by and partially determined by the operating parameters of the torque converter. One of the measures of torque converter performance is the “K-factor.” The K-factor is the ratio of the input speed of the torque converter to the square root of the torque output of the engine, as measured at any torque converter operating point. In turn, the “operating point” of a torque converter is typically defined by the ratio of the output speed to the input speed which is also known as the speed ratio.
All things being equal, it is desirable to achieve a low K-factor across the entire speed ratio range. Increased efficiency of energy transfer through a torque converter is also a highly desirable goal. The present invention is directed to a torque converter which achieves both goals.